Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf78a2dde00113d1…

MALICIOUS

PDF

84.8 KB Created: 2021-06-29 22:52:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: f3e6eaff2e3de998bcdca6a0e0a4d787 SHA-1: ab4d8cdb7757044122ddae9d0d6457256c52bec1 SHA-256: cf78a2dde00113d102fe23755d401f6be621e7856da6ecdfdf65d3114a1ffbba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm on compromised WordPress sites, with numerous distinct hosts and URLs pointing to PDF files. The embedded URLs suggest a phishing or malware distribution attempt, likely using the document as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/f3fc6aee7ef930577ce1ea364b19968f/91401660086.pdf In PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/f01d16088e988ea161cbe242215e0ea0/bapez.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1606e6e355e008---75950997685.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609831d2f0a05---dokenekukefi.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911f5260e45---muvividemuzobu.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/f592ad5fc4362dd13b9455023f782534/tariwibuwenubud.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/c0b3f890ccfdee475bceb3c03280a0bd/waratolilidujawer.pdfIn PDF document text
    • http://www.onlinetemsilci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160702cb974bd2---tebibekonujageretakape.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/1b3d4ee8f4c5bd7d29627fc6b03e1da9/midedirogedu.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/e5k25hchndmsjjc0g7u9a5no04/95661313580.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/67tnc3lknae5mpkppvsggids96/70466078565.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa34cf37d89---45347690454.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/dv7b17nhd30rppn7307t0o0tsk/42416858525.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af71163fd32---61772353064.pdfIn PDF document text
    • http://bukharajohnscreek.com/sites/default/files/file/dabanaxazobumilabonum.pdfIn PDF document text
    • https://unicornccc.com/ckfinder/userfiles/files/janirewowedij.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16079ce902339f---givagajotujugebovifiresoz.pdfIn PDF document text
    • http://eaas-journal.org/survey/userfiles/files/67047798951.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb6172e98a---36061047035.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/a88aae7b19328e26341f7ed19d5834ef/43607470567.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/51994070627.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/megagetubebalugidoba.pdfIn PDF document text
    • https://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/mmn3c19r4ag3u6nv0aanagp2c4/41156679782.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160bc76fd5e7f0---71083789432.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=bewildered+meaning+in+gujaratiPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c8e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8E4 18660 bytes
SHA-256: 8b0d48d126c5cb92bbafa1d19a813947e9111b11bd0932e59123a55815881520
font_01_sfnt_off0000f97e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF97E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011195.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11195 10672 bytes
SHA-256: 763704f022ae6549982b06bd2a64ac93a0f13e1d9e56db8d3971ab1a3f4bd636
font_03_sfnt_off000129c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129C5 17228 bytes
SHA-256: 47e8562391740b40642251c6926f2b31a0199911f564c3159dd874033d7ad583